Mechanical ore-roasting furnace.



J. HARRIS. MECHANICAL ORE ROASTING FURNACE.

APPLICATION FILED JUNE 2l 1911.

Patented Aug. 13, 1912.

2 SHEETS-SHBET 1.

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J. HARRIS.

MECHANICAL ORE ROASTING I'URNAGE. APPLIoATIoN FILED JUNE 2, 1911.

1,085, 186. R Patented Aug. 13, 1912.

., 2 SHBBTMAEBET 2.

sectional plan taken on. vthe line 2-2 of Fig.

.the drawings.

JOHN HARRIS, OF SH EFFIELD, ENGLAND.

MECHANICAL OREROASTING FURNACE..

1,035,186. Specification of team rama. Patented Aug.. 13,1912.

Application led June 2, 1911. Serial No. 830,757.

Tov all whom it may concern:

Be it known that I, JOHN Harms, a subject of the King of England,residing in Sheflield, in the county of York, England, have inventedcertain new and useful Improvements in or Relating to MechanicalOre-Boasting Furnaces, of which the following is a specification.

This invention relates to mechanical ore roasting furnaces and has forits object toy provide improvements in the construction and operationthereof, whereby a portion of the furnace may be cooled for any purpose,such as effecting repairs or renewals, without interfering with thecontinuous o eration of the remainder of the furnace, and whereby such acooled portion may be reheatcd without using coal or like fuel.Her'etofore even they smallest breakdown inside has neccssitated thewhole furnace being cooled down, and after the repair has been made, thefurnace has had to be lighted up again with coal or like fuel, resultingin its being idle for many days or even for two or three weeks. By theemployment of the present invention, however, a breakdown can berepaired or a renewal effected with greater ease than heretofore andwithout stopping the whole furnace, and afterward considerable time issaved in reheating the cooled portion by the hot gases from theremainder of the furnace which has been in continuous operation whilethe repair or renewal has been made. By the employment of this inventionalso the dust raised in the furnace is reduced to a minimum with theconsequent increase of purity in the acid obtained when dealingwithsulfur ores. Means are also provided for enablin when desired, aconcentration of heat to ie effected upon, or auxiliary heat to bedirected upon a portion of the furnace.

In the accompanying drawingsz-Figure 1 is 'a longitudinal section of afurnace according to this invention, the section being taken on the line1-1 of Fig. 2 which is a 1. Fig. 3 is a transverse section taken on theline 3-3 of Fig. 2 and Fig. 4 is a trans-Y verse section on the line kwain Figs. l and 2.

Like letters indicate like parts throughout A\ furnace according. tothis-invention is l built in two or more vertical sections, three beingshown in the drawings separated by walls A. Each section comprises aplurality of superimposed hearths in the form of arched floors or thelike B which thus divide the section into the desired number of tiers orcompartments. a pair of vert-ical rake shafts C carryiiuir a rake D ineach tier. A space is provided eneath the lowest floor B in each sectionto form a dust chamber E. One or,n'\ore vertical flues F are providedfor each section communicating with the dust chamber E at t-he bottomand with an exit flue or channel Gr at the top leading to the acidforming tower or chimney. 'lhe [lues F of each section also communicateby a suitable port with the uppermost tier thereof and two dampers H andH1 (Figs. 1, 3 and Il) are provided adjacent to such communicatingaperture so that the gases from the interior may be led either to thechannel Gr or to the dust chamber E by manipulating these dampers. Anaperture J controlled by a damper J1 is provided between the dustchamber E and the lowest tier of each section, and similar openings J 2are also made in the arched floors B separating the various compartmentsof the section. The apertures J 2 are preferably arranged at alternateends of successive floors B as shown in Fig. 3, those adjacent to theflue F being conveniently formed by an enlargement of the hole in thefloor through which the rake shaft C at this end passes.

In each section there is The rake shafts C are mountedv on suitable p0pcdestals separated from the interior of the dust chamber bycompartments K. The two rakes D in each tier are arranged so that theirpaths overlap only a comparatively short distance as indicated by thecircles Dp in the central section shown in Fig. 2. The ore to be roastedis fed through a suitable feed aperture Lin the roof o the furnace (Fig.3) adjacent to the center of one of the rakes in theupperinost tier. Theblades on this rake are so arranged in relation to its sense ofrot-ation that the ore is gradually moved'toward the circumference oftherake path, where it comes under the action of the other rake in thattire whdse blades-are arranged to move the ore toward its shaft t0 ayfeed opening L1 adjacent thereto whence the ore passes to the next tierand so on until it ies is finally delivered from the lowermost tier. InFig. 3 rakes D1 are also shown above the roof of the furnace and in thisway the heat of the roof may be employed to dry damp ores.

The dust chambers E communicate with one another by means of ports orpassages M (Fig. 2) in the separating walls A. F lues N are providedleading from the series of dust chambers to the acid forming tower onchimney (either directly or by joining the exit flue Gr).

In operation the dampers H are open and H1 and J1 closed, the gases fromeach sect-ion passing from the uppermost .tier direct to the channel G.If too much dust inds its way through the channel G, the gases from thesection or sections causing the dust may be passed through the chambersE in order that the dust may settle therein, by closing the dampers Hand opening H1. From the chambers E the gases will pass to the chan` nelG by way of the flues N or their equiva-V lent or through one section bywayof the ports M and opening J. ln case it is desired to permit anysection to become cool, as for instance to make repairs or renew somepart thereof, the generation of gases therein is prevented by cuttingoff the vfeed of ore thereto. rilhe cooling maybe, and prefer ably is,expedited by opening the damper* J1 and closing the dampers H and H1 ofthe section to be cooled, and by opening to their fullest extent the airinlets A1 of that section which, as is well known, it is necessary toprovide in all ore roasting furnaces to supply the air necessar for thecombustion of the sulfur container in the ore. It will thus be seen thatthe discontinuance of such section is edected without interfering withthe continuous operation of other sections. The cold section or sectionsmay be reheated quickly and easily without the use of coal or like fuelby feeding the ore (slowly at first) and directing the hot gases fromthe other section or sections through it by clos'- ing the dampers H andopening H1 of the hot section, and opening the dampers J1 and H andclosing H1 of the cold sectio'n. The hot gases from the section. inoperation will then pass into its dust chamber and thence as indicatedon the left hand side of Fig. 2 through the ports M and Jl into andthrough the various tiers of the cold section and iin ally into thechannel G. The rods tying the lower ends of the girders supporting thefurnace are preferablyarranged in channels beneath the dust chamber asshown diagrammatically at Q. These channels have one end open to theatmosphere, the other being suitably connected to an air inlet openingof the. furnace. A double advantage is thusq obtained, the current ofair passing alonou the' channels to the furnace being delivere theretoin a heated condition andthe tie iary heat is required. This isespecially the case with zinc and copper sulid ores which would stillretain a small proportion of sulfur if treated simply in the mannerdescribed above. To complete the roasting of such ores and thoroughly toeliminate the sulfur therefrom a furnace according to this invention ismodified as indicated in Fig. 4 and in the left hand section shown inFig. 1 by providing a flat false floor O (conveniently of tiles) a shortdistance above the arched floor B of the lowermost tier, lthis floor Bbeing preferably arranged somewhat farther below the one above it thanwould otherwise be the case. `The floor O is supported on this arch by anumber of transyverse walls extending from one side of the sectiony butnot quite reaching the opposite side and alternately arranged so as toprovide also a baiiled passage between the lowest arch B and the floorO. At one end Aof the section this passage is opengto one or more of thefiues F a damper P being arranged below sueh openin yor otherwise sothat hot gases fromthe ue F may be directed into this passage. At theother end the passage may be provided with a ue leading to the channel Gor is as shown open to the port or ports J. In .the latter case two damers J1 and J? are 'furnished for the port the upper one J1 is only opento heat the section by the hot gases from other sections, while thelower one J 3 is also used to open a path between the passage under theHoor O and the dustv chamber E. I It will thus be appreciated that thehot gases emerging from the uppermost tier of a section may be directedthrough the baliied passage beneath the flat door O in order to providethev auxiliary heat necessary com- -pletely to eliminate the sulfur fromcertain ters Patent is What I claim and desire to secure by Leti l. In aroasting furnace of the described the combination of segregated sectionsthereof, and means for connecting the space above the uppermost hearthof one section with that above the lowermost set forth.

hearthl of another section for the purpose 2. In a roasting furnace ofthe kind den i scribed the combinationof segregated 'cections thereof,an eX-it flue, a dust chamber, a. passage )between the dust chamber andeach sectiomdampers controlling said passages, a flue for each sectioncommunicating with the exit ue and with the dust chamber, a port betweeneach section and its flue,

a damper in each section Hue between said ort and the exit Hue and asecond damper 1n each section Hue between said port and the dust chamberfor the purpose set forth.

3. In a roasting furnace of the kind described the combination ofsegregated sections thereof each comprising a plurality of superimposedhear'ths, an exit i chamber, a passage between the dust chamber and eachsection, dampers controlling said passages, a Hue for each sectioncommunicating with the exit flue and with the dust chamber, a portbetween each section and its Hue, a damper in each section Hue betweensaid port and the exit Hue, a second damper in each section Hue bctwccnsaid port and the dust chamber, an outlet Hue from the dust chamber, apassage below the lowermost hearth in each section and means forsupplying heat to said passage for the purpose set forth.

4. In a roasting furnace of the kind dcscribed the combination ofsegregated sections thereof each comprising a plurality of superimposedhearths, an exit Hue, a dust chamber, a passage between the dust chamberand each section, dampcrs controlling said passages, a Hue for eachsection communicating with the exit Hue and with the dust chamber, aport between each Section and its Hue, a damper in cach section Huebetween said port and the exit Hue, a second damper in each section Huebetween said port and the dust chamber, an outlet Hue from the dustchamber, a passage below the lower-most hearth in each section and meansfor dircctinglthe products of combustion from the section Hue throughsaid passage .to the dust chamber for the purpose set forth.

In testimony whereof I have signed' my name to this speciication in thepresence o two subscribing. witnesses.

JOHN HARRIS.

Witnesses ARTHUR Il. GREENWOOD,

Enrri-I A. Pon'rEUs.

